Add basic support for unknown (zero) sized mdat boxes in AVIF. Ideally, the BMFFBoxcontents would be limited to the remaining size of the file and everything would just work, but the file length is not available via the Mp4ParseIo interface (and may not be query-able for some streams) so it's not possible to rely on that. Instead, when encountering a zero sized mdat, read the remaining file in chunks until end of file.
This partially addresses the issue reported in BMO 1805436.
Add basic support for unknown (zero) sized
mdatboxes in AVIF. Ideally, theBMFFBoxcontentswould be limited to the remaining size of the file and everything would just work, but the file length is not available via theMp4ParseIointerface (and may not be query-able for some streams) so it's not possible to rely on that. Instead, when encountering a zero sizedmdat, read the remaining file in chunks until end of file.This partially addresses the issue reported in BMO 1805436.